In known wall boards of this type, the board member is arranged in front of the board support, so that the latter is visible from the side. The board member has, optically, no connection to the wall surface. In this arrangement, the board support mechanism is exposed to much dirt and dust. Also, breakdowns can occur due to solid articles, for example drawing utensils, getting into the board support and blocking the board support mechanism. Also, the danger of injuries exists, since manual reaching into the board support mechanism is possible, whereby in particular injuries to the hand are to be feared. Finally, the appearance of the known boards is also not pretty, since an optical connection of the board member to the wall surface does not exist and the board member, because of its elevational adjustability, is in a changing three-dimensional arrangement with respect to the board support.
A basic purpose of the invention is thus to provide a wall board of the above-mentioned type in which the board support is not visible, so that the mentioned disadvantages are avoided.
This purpose is attained according to the invention by providing vertical side walls on the board member which project rearwardly from the back of the board member and extend along or near the side edges of the board member, and by arranging guide rails on the inner sides of these side walls, which guide rails receive guide slide pieces or guide rollers provided on the board support, the side walls covering the board support laterally and extending approximately to the wall.
In a thusly constructed wall board, the board support mechanism is covered by the side walls and thus is not visible. Due to the side walls extending rearwardly to a location close to the wall, there exists optically a connection of the board member to the wall, which substantially improves the appearance of the wall board. Manually reaching into the board support mechanism from the side is not possible, through which the danger of injuries is reduced. Also, falling of solid articles into the board support mechanism is not possible. A board according to the invention is particularly suitable for use in presentation rooms, for example conference rooms. However, it is also suitable for many other uses, for example for equipping schools.
The wall board advantageously has a weight balancing device which is arranged on the board support and includes a counterweight or at least a counterspring. A conventional balancing device can be utilized here, which device is of the type usually used for school wall boards and can be provided in a wall board support. A special embodiment for such a balancing device involves a counterweight which moves in a direction opposite to the board. However, one can also achieve a weight balance through a spring force, whereby during lowering of the board, energy is stored in the spring and, during lifting of the board, energy is recovered from the spring. In a balancing device with a counterweight, resilient stops are advantageous in order to avoid hard impacts of the counterweight at the end positions.
In a preferred embodiment of the invention, each side wall and the guide rail associated with it are manufactured as one piece, preferably as an extrusion of aluminum. Through this, one obtains low manufacturing costs, particularly in the case of a series manufacture on a large scale. Also, arrangements within the scope of the invention include, for example, plates used as side walls and guide rails which are separate parts connected to the plates. The guide rails can have a U-shaped or C-shaped cross section. Such guide rails have the advantage that guide slide pieces and guide rollers are guided toward several sides, and in the case of a C-shaped cross section a lateral moving out of the rollers from the guide rail is not possible.
Important advantages are achieved if just side walls are provided. According to a preferred embodiment, however, walls are also provided above and below the board support. For the protection of the board support mechanism, it is particularly important to provide the upper wall, since it provides protection from dust and solid articles falling from above.
However, a lower wall also improves the wall board, because manually reaching into the board mechanism from below is no longer possible. In the case of two side walls, an upper wall and a lower wall, the board frame is completely surrounded by walls and thus protected all around.
The upper wall and the lower wall can also be extrusions, which are advantageously constructed as hollow profiles. A different profile than that used for the side walls is advisable because the horizontal walls do not need to have guide rails.
The walls are connected advantageously by means of corner pieces. The use of such corner pieces avoids the need for mitre cuts. Also, an advantageous shape is possible, since the special corner pieces permit a rounding of the corner regions.
The corner pieces are preferably constructed so that, during mounting of the board, the horizontal walls can be initially left out and then, after mounting of the board member on the board support mechanism, can be quickly mounted and can be secured in place by means of longitudinal screws. Also, the longitudinal screws can be made invisible by providing a cover plate thereover.
For a weight balancing device in which the balancing weight covers a vertical path which is as long as the vertical path of the board, the height of the board support is preferably approximately half that of the board member. The entire vertical path of movement of the board member is then approximately half the height of the board surface. However, constructions are also possible in which the height of the board support is less in relationship to the height of the board member. Such constructions are possible where the counterweight moves a smaller distance than the board member or where a weight balancing device with springs is used. In this case, the possible path of movement of the board member can be greater than half the height of the board surface. Particularly suitable and optically appealing is a square board member, even though this shape is not essential for realizing the invention.